European contribution to the study of ROS: A summary of the findings and prospects for the future from the COST action BM1203 (EU-ROS)

A reactive oxygen species-related signature predicts the prognosis and immunosuppressive microenvironment in gliomas

OBJECTIVE

Intracellular redox homeostasis is crucial for a series of physiological processes. Reactive oxygen species (ROS) play important roles in redox processes. ROS can maintain cell reproduction and survival at moderate levels while promoting the initiation and progression of tumors at high levels.

METHODS

Based on a comprehensive analysis of ROS-related gene expression profiles, we established a gene signature associated with ROS to explore its influence on prognosis and immune microenvironment in gliomas.

RESULTS

The ROS-related gene expression profile dichotomized patients into two groups with different clinicopathological features and prognoses. A 19-gene ROS-related signature was used to robustly predict prognosis in both training and validation datasets. Functional analysis indicated an association between ROS levels and the immune microenvironment. The expression of immune checkpoints and M2-type markers was upregulated in the high-risk group, which suggested the immunosuppressive function of ROS.

CONCLUSION

ROS-related signature is an independent prognostic factor in gliomas and could potentially exert immunosuppressive effects on the tumor microenvironment.

Role of MTH1 in oxidative stress and therapeutic targeting of cancer

Cancer cells maintain high levels of reactive oxygen species (ROS) to drive their growth, but ROS can trigger cell death through oxidative stress and DNA damage. To survive enhanced ROS levels, cancer cells activate their antioxidant defenses. One such defense is MTH1, an enzyme that prevents the incorporation of oxidized nucleotides into DNA, thus preventing DNA damage and allowing cancer to proliferate. MTH1 levels are often elevated in many cancers, and thus, inhibiting MTH1 is an attractive strategy for suppressing tumor growth and metastasis. Targeted MTH1 inhibition can induce DNA damage in cancer cells, exploiting their vulnerability to oxidative stress and selectively targeting them for destruction. Targeting MTH1 is promising for cancer treatment because normal cells have lower ROS levels and are less dependent on these pathways, making the approach both effective and specific to cancer. This review aims to investigate the potential of MTH1 as a therapeutic target, especially in cancer treatment, offering detailed insights into its structure, function, and role in disease progression. We also discussed various MTH1 inhibitors that have been developed to selectively induce oxidative damage in cancer cells, though their effectiveness varies. In addition, this review provide deeper mechanistic insights into the role of MTH1 in cancer prevention and oxidative stress management in various diseases.

Oxidative Stress and Antioxidants in Pediatric Asthma's Evolution and Management

Within the pediatric population, bronchial asthma is one of the most prevalent chronic respiratory system diseases. The number of exacerbations, severity, and duration of symptoms all have a significant impact on children's life quality. In the last decades, the prevention and management strategies of this pathology have focused on maintaining or even increasing the pulmonary function to maximum levels in early childhood, as it has been demonstrated that functional deficits at this level occurring before school age cause pathological manifestations later, in adulthood. The epithelium of the airways and implicitly that of the lung is the first barrier against the lesions caused by pro-oxidative factors. Both oxidative and antioxidative factors can be of endogenous origin (produced by the body) or exogenous (from the environment or diet). Good functioning of antioxidant defense mechanisms from the molecular level to the tissue level, and a balance between pro-oxidative factors and anti- oxidative factors, influence the occurrence of compensatory mechanisms at the level of the respiratory epithelium, causing the delay of local responses to the stress induced by chronic inflammation (bronchial remodeling, thickening of airway smooth muscles, bronchoconstriction, bronchial hyper-reactivity). These mechanisms underlie the pathophysiological changes in asthma. Numerous studies carried out among the pediatric population inclusively have demonstrated the effectiveness of antioxidants in the prophylaxis, slowing down and preventing the progression of this pathology. This review complements the scientific articles, aiming at emphasizing the complexity of oxidative physio-pathological pathways and their importance in the occurrence, development, and therapeutic response in asthma, providing a good understanding of the relationship between oxidative and antioxidative factors, and being a source of future therapeutic strategies.

Tapinarof and its structure-activity relationship for redox chemistry and phototoxicity on human skin keratinocytes

Tapinarof (3,5-dihydroxy-4-isopropylstilbene) is a therapeutic agent used in the treatment of psoriasis (VTAMA®). In this study, we examined the redox behaviour, (photo)stability, (photo)toxicity and (bio)transformation of tapinarof in the context of a structure-activity relationship study. Selected derivatives of the structurally related tapinarof were investigated, namely resveratrol, pterostilbene, pinosylvin and its methyl ether. Tapinarof undergoes electrochemical oxidation in a neutral aqueous medium at a potential of around +0.5 V (vs. Ag|AgCl|3M KCl). The anodic reaction of this substance is a proton-dependent irreversible and adsorption-driven process. The pKa value of tapinarof corresponds to 9.19 or 9.93, based on empirical and QM calculation approach, respectively. The oxidation potentials of tapinarof and its analogues correlate well with their HOMO (highest occupied molecular orbital) energy level. The ability to scavenge the DPPH radical decreased in the order trolox ≥ resveratrol > pterostilbene > tapinarof > pinosylvin ≫ pinosylvin methyl ether. It was also confirmed that tapinarof, being a moderate electron donor, is able to scavenge the ABTS radical and inhibit lipid peroxidation. The 4'-OH group plays a pivotal role in antioxidant action of stilbenols. During the stability studies, it was shown that tapinarof is subject to spontaneous degradation under aqueous conditions, and its degradation is accelerated at elevated temperatures and after exposure to UVA (315-399 nm) radiation. In aqueous media at pH 7.4, we observed an ∼50 % degradation of tapinarof after 48 h at laboratory temperature. The main UVA photodegradation processes include dihydroxylation and hydration. In conclusion, the phototoxic effect of tapinarof on a human keratinocytes cell line (HaCaT) was evaluated. Tapinarof exhibited a clear phototoxic effect, similar to phototoxic standard chlorpromazine. The IC50 values of the cytotoxicity and phototoxic effects of tapinarof correspond to 27.6 and 3.7 μM, respectively. The main HaCaT biotransformation products of tapinarof are sulfates and glucuronides.

The role of polydatin in inhibiting oxidative stress through SIRT1 activation: A comprehensive review of molecular targets

ETHNOPHARMACOLOGICAL RELEVANCE

Reynoutria japonica Houtt is a medicinal plant renowned for its diverse pharmacological properties, including heat-clearing, toxin-removing, blood circulation promotion, blood stasis removal, diuretic action, and pain relief. The plant is commonly utilized in Traditional Chinese Medicine (TCM), and its major bioactive constituents consist of polydatin (PD) and resveratrol (RES).

AIM OF THE STUDY

To summarize the relevant targets of PD in various oxidative stress-related diseases through the activation of Silence information regulator1 (SIRT1). Furthermore, elucidating the pharmacological effects and signaling mechanisms to establish the basis for PD's secure clinical implementation and expanded range of application.

MATERIALS AND METHODS

Literature published before November 2023 on the structural analysis and pharmacological activities of PD was collected using online databases such as Google Scholar, PubMed, and Web of Science. The keywords were "polydatin", "SIRT1" and "oxidative stress". The inclusion criteria were research articles published in English, including in vivo and in vitro experiments and clinical studies. Non-research articles such as reviews, meta-analyses, and letters were excluded.

RESULTS

PD has been found to have significantly protective and curative effects on diseases associated with oxidative stress by regulating SIRT1-related targets including peroxisome proliferator-activated receptor γ coactivator 1-alpha (PGC-1α), nuclear factor erythroid2-related factor 2 (Nrf2), high mobility group box 1 protein (HMGB1), NOD-like receptor thermal protein domain associated protein 3 (NLRP3), p38/p53, as well as endothelial nitric oxide synthase (eNOs), among others. Strong evidence suggests that PD is an effective natural product for treating diseases related to oxidative stress.

CONCLUSION

PD holds promise as an effective treatment for a wide range of diseases, with SIRT1-mediated oxidative stress as its potential pathway.

Impact of the redox-active MnTnHex-2-PyP5+ and cisplatin on the metabolome of non-small cell lung cancer cells

Redox-based cancer therapeutic strategies aim to raise reactive oxygen species (ROS) levels in cancer cells, thus modifying their redox status, and eventually inducing cell death. Promising compounds, known as superoxide dismutase mimics (SODm), e.g. MnTnHex-2-Py5+ (MnTnHex), could increase intracellular H2O2 in cancer cells with deficient ROS removal systems and therefore enhance radio- and chemotherapy efficacy. We have previously shown that MnTnHex was cytotoxic either alone or combined with cisplatin to non-small cell lung cancer (NSCLC) cells. To gain a deeper understanding of the effects and safety of this compound, it is crucial to analyze the metabolic alterations that take place within the cell. Our goal was thus to study the intracellular metabolome (intracellular metabolites) of NSCLC cells (A549 and H1975) using nuclear magnetic resonance (NMR) spectroscopy-based metabolomics to evaluate the changes in cellular metabolism upon exposure to MnTnHex per se or in combination with cisplatin. 1H NMR metabolomics revealed a higher number of significantly altered metabolites in A549 cells exposed to MnTnHex alone or combined with cisplatin in comparison with non-treated cells (nine dysregulated metabolites), suggesting an impact on aminoacyl-tRNA biosynthesis, glycolysis/gluconeogenesis, taurine, hypotaurine, glycerophospholipid, pyruvate, arginine and proline metabolisms. Regarding H1975 cells, significant alterations in the levels of six metabolites were observed upon co-treatment with MnTnHex and cisplatin, suggesting dysregulations in aminoacyl-tRNA biosynthesis, arginine and proline metabolism, pyruvate metabolism, and glycolysis/gluconeogenesis. These findings help us to understand the impact of MnTnHex on NSCLC cells. Importantly, specific altered metabolites, such as taurine, may contribute to the chemosensitizing effects of MnTnHex.

Advances in clinical application of lipidomics in healthy ageing and healthy longevity medicine

It is imperative to optimise health and healthspan across the lifespan. The accumulation of reactive oxygen species (ROS) has been implicated in the hallmarks of ageing and inhibiting ROS production can potentially delay ageing whilst increasing healthy longevity. Lipids and lipid mediators (derivatives of lipids) are becoming increasingly recognized as central molecule in tissue and cellular function and are susceptible to peroxidation; hence linked with ageing. Lipid classes implicated in the ageing process include sterols, glycerophospholipids, sphingolipids and the oxidation products of polyunsaturated fatty acids but these are not yet translated into the clinic. Further mechanistic studies are required for the understanding of lipid classes in the ageing process. Lipidomics, the system level characterisation of lipid species with respect to metabolism and function, might provide a significant and useful biological age profiling tool through longitudinal studies. Lipid profiles in different ages among healthy individuals could be harnessed as lipid biomarkers of healthy ageing with potential integration for the development of lipid-based ageing clock (lipid clock). The potential of a lipid clock includes the prediction of future morbidity or mortality, which will promote precision and healthy longevity medicine.

Differential Regulation of Wingless-Wnt/c-Jun N-Terminal Kinase Crosstalk via Oxidative Eustress in Primary and Metastatic Colorectal Cancer Cells

In the tumor microenvironment (TME), ROS production affects survival, progression, and therapy resistance in colorectal cancer (CRC). H2O2-mediated oxidative stress can modulate Wnt/β-catenin signaling and metabolic reprogramming of the TME. Currently, it is unclear how mild/moderate oxidative stress (eustress) modulates Wnt/β-catenin/APC and JNK signaling relationships in primary and metastatic CRC cells. In this study, we determined the effects of the H2O2 concentration inducing eustress on isogenic SW480 and SW620 cells, also in combination with JNK inhibition. We assessed cell viability, mitochondrial respiration, glycolysis, and Wnt/β-catenin/APC/JNK gene and protein expression. Primary CRC cells were more sensitive to H2O2 eustress combined with JNK inhibition, showing a reduction in viability compared to metastatic cells. JNK inhibition under eustress reduced both glycolytic and respiratory capacity in SW620 cells, indicating a greater capacity to adapt to TME. In primary CRC cells, H2O2 alone significantly increased APC, LEF1, LRP6, cMYC and IL8 gene expression, whereas in metastatic CRC cells, this effect occurred after JNK inhibition. In metastatic but not in primary tumor cells, eustress and inhibition of JNK reduced APC, β-catenin, and pJNK protein. The results showed differential cross-regulation of Wnt/JNK in primary and metastatic tumor cells under environmental eustress conditions. Further studies would be useful to validate these findings and explore their therapeutic potential.

Camphene as a Protective Agent in Myocardial Ischemia/Reperfusion Injury

Myocardial ischemia/reperfusion injury (I/R) and the resulting heart failure is one of the main causes of mortality and morbidity worldwide. Camphene has been shown to have anti-inflammatory and hypolipidemic properties; however, its role in the protection of the heart from ischemia and reperfusion has not been investigated. The cardioprotective role of camphene and the mechanism that mediates its action against I/R injury was evaluated in the present study. A single dose of camphene was administered in adult rats prior to ex vivo I/R induction. Infarct size was measured using 2,3,5-triphenyltetrazolium chloride (TTC) staining and cardiomyocyte injury was assessed by determining the release of the enzyme lactate dehydrogenase (LDH). Camphene pretreatment provided significant protection reducing myocardial infarct size and cell death after I/R. The effect was correlated with the reduction in oxidative stress as evidenced by the determination of protein carbonylation, GSH/GSSG ratio, the increase in mitochondrial content as determined by CS activity, and the modulation of antioxidant defense mechanisms (expression of Nrf2 and target genes and activities of CAT, MnSOD, and GR). Furthermore, ferroptosis was decreased, as demonstrated by downregulation of GPx4 expression and reduction in lipid peroxidation. The results suggest that camphene can protect the heart against I/R injury by maintaining redox homeostasis and can hold therapeutic potential for mitigating the detrimental effects of I/R in the heart.

Current trends in targeting the oxidative stress in glaucoma (Review)

Glaucoma is a progressive optic neuropathy characterised by retinal ganglion cell degeneration and visual field loss. Glaucoma is considered to be the leading cause of blindness in the industrialised countries. Oxidative damage is an important pathogenic factor in glaucoma, which triggers trabecular meshwork (TM) degeneration, which then leads to intraocular hypertension. Neurodegenerative insults during glaucomatous neurodegeneration initiate an immune response to restore tissue homeostasis. However, the oxidative stress (OS) that develops during the pathogenic processes of glaucoma, along with the agerelated OS, plays a critical role in shifting the physiological equilibrium. In the TM from glaucoma donors, proinflammatory markers were found, which were induced by the activation of a stress response. Chronic changes in the composition of antioxidants found in aqueous humour may induce alterations in TM as well as in the optic nerve head cells. Highlighting the pathogenic role of reactive oxygen species (ROS) in glaucoma has implications in preventing this disease. Various clinical trials are available to test the efficacy of antioxidant drugs in glaucoma management. In this review, we discuss the OS as a therapeutic target, suggesting that the modulation of a pro-oxidant/antioxidant status might be a relevant target for glaucoma prevention and therapy.

Health position paper and redox perspectives - Disease burden by transportation noise

Transportation noise is a ubiquitous urban exposure. In 2018, the World Health Organization concluded that chronic exposure to road traffic noise is a risk factor for ischemic heart disease. In contrast, they concluded that the quality of evidence for a link to other diseases was very low to moderate. Since then, several studies on the impact of noise on various diseases have been published. Also, studies investigating the mechanistic pathways underlying noise-induced health effects are emerging. We review the current evidence regarding effects of noise on health and the related disease-mechanisms. Several high-quality cohort studies consistently found road traffic noise to be associated with a higher risk of ischemic heart disease, heart failure, diabetes, and all-cause mortality. Furthermore, recent studies have indicated that road traffic and railway noise may increase the risk of diseases not commonly investigated in an environmental noise context, including breast cancer, dementia, and tinnitus. The harmful effects of noise are related to activation of a physiological stress response and nighttime sleep disturbance. Oxidative stress and inflammation downstream of stress hormone signaling and dysregulated circadian rhythms are identified as major disease-relevant pathomechanistic drivers. We discuss the role of reactive oxygen species and present results from antioxidant interventions. Lastly, we provide an overview of oxidative stress markers and adverse redox processes reported for noise-exposed animals and humans. This position paper summarizes all available epidemiological, clinical, and preclinical evidence of transportation noise as an important environmental risk factor for public health and discusses its implications on the population level.

Nutrigenomics and redox regulation: Concepts relating to the Special Issue on nutrigenomics

During our whole lifespan, from conception to death, the epigenomes of all tissues and cell types of our body integrate signals from the environment. This includes signals derived from our diet and the uptake of macro- and micronutrients. In most cases, this leads only to transient changes, but some effects of this epigenome programming process are persistent and can even be transferred to the next generation. Both epigenetic programming and redox processes are affected by the individual choice of diet and other lifestyle decisions like physical activity. The nutrient-gene communication pathways have adapted during human evolution and are essential for maintaining health. However, when they are maladaptive, such as in long-term obesity, they significantly contribute to diseases like type 2 diabetes and cancer. The field of nutrigenomics investigates nutrition-related signal transduction pathways and their effect on gene expression involving interactions both with the genome and the epigenomes. Several of these diet-(epi)genome interactions and the involved signal transduction cascades are redox-regulated. Examples include the effects of the NAD+/NADH ratio, vitamin C levels and secondary metabolites of dietary molecules from plants on the acetylation and methylation state of the epigenome as well as on gene expression through redox-sensitive pathways via the transcription factors NFE2L2 and FOXO. In this review, we summarize and extend on these topics as well as those discussed in the articles of this Special Issue and take them into the context of redox biology.

L-glutathione 1% promotes neuroprotection of nitrergic neurons and reduces the oxidative stress in the jejunum of rats with Walker-256-bearing tumor

AIMS

Our main goals were to investigate the effects of L-glutathione (1%) treatment in Walker-256 tumor-bearing rats by analyzing immunoreactive neurons (IR), responsive to the nNOS enzyme and 3-Nitrotyrosine, in their jejunum myenteric plexus. Moreover, the oxidative state and inflammatory process in these animals were investigated.

METHODS

Four experimental groups were utilized: control (C), control treated with L-glutathione (CGT), Walker-256 tumor-bearing rats (TW), and Walker-256 tumor-bearing rats treated with L-glutathione (TWGT). After 14 days of tumor inoculation, the jejunum was collected for immunohistochemical techniques and assessment of oxidative status. Plasma was collected to evaluate oxidative status and measure cytokines.

RESULTS

The TW group exhibited a decrease of reduced glutathione in their jejunum, which was prevented in the L-glutathione treated TWGT group. TW animals presented pronounced oxidative stress by increasing levels of lipoperoxidation in their jejunum and malondialdehyde in their plasma; however, the L-glutathione treatment in TWGT group was not able to avoid it. The total antioxidant capacity was altered in groups TW and TWGT, yet the last one had a better index in their plasma. The IL-10, and TNF-α levels increased in TWGT animals. The nNOS-IR neuron density decreased in the jejunum myenteric plexus of the TW group, which was avoided in the TWGT group. The nNOS +3-Nitrotyrosine neurons quantification did not show significative alterations.

CONCLUSION

The treatment with L-glutathione (1%) imposed an important defense to some parameters of oxidative stress induced by TW-256, leading to neuroprotection to the loss in the nNOS-IR neuron density.

L-shaped association of serum α-Klotho and frailty among the middle-aged and older adults: results from NHANES 2007-2016

BACKGROUND

Frailty is common and not limited to older age group. Serum α-Klotho works as a biomarker of anti-aging effect. However, there is limited research about the relationship between them in middle-aged and older people and controversy still exists.

METHODS

Based on data from National Health and Nutrition Examination Survey (NHANES) 2007-2016, we constructed weighted logistic regression models and conducted sensitivity tests to investigate the correlation between frailty and α-Klotho among people aged 40 to 79. And then their relationship was visualized by Restricted Cubic Spline (RCS). Finally, the stratified analyses and interaction tests of covariables was presented in the forest plot.

RESULTS

A total of 7052 individuals were involved in this study, with mean age of 62.76 ± 0.18 years and females accounting for 51.05%. 2554 of them were in "frailty". After adjustment for relevant covariables, weighted logistic regression models showed that the odds ratio and 95% confidence interval [ORs (95%CI)] of correlation between frailty and Natural Logarithm(ln)-transformed α- Klotho[ln(α-Klotho)] was 0.63 (0.50, 0.79); we then performed a sensitivity analysis and found that the results remained stable. In model 3, individuals in quartiles 2, 3, and 4 showed statistical differences compared with the lowest ln(α-Klotho) quartiles, ORs (95% CI) were 0.74 (0.59, 0.93), 0.72 (0.57, 0.91), 0.71 (0.57, 0.87), respectively. Subsequently, non-linear associations were exhibited by RCS (p<0.001). The turning point for α-Klotho and ln(α-Klotho) were 785.7(pg/ml) and 6.67, respectively. Finally, analysis of the relationship between different levels of ln(α-Klotho) and frailty in different populations revealed differences between groups. The results of the interaction test showed that no other covariables had significant interaction with serum α-Klotho in our study.

CONCLUSION

The L-shaped and negative correlation was found between α-Klotho and frailty among people aged 40 to 79 in the NHANES from 2007 to 2016.

Circulating and Urinary Concentrations of Malondialdehyde in Aging Humans in Health and Disease: Review and Discussion

(1) Background: Malondialdehyde (MDA) is a major and stable product of oxidative stress. MDA circulates in the blood and is excreted in the urine in its free and conjugated forms, notably with L-lysine and L-serine. MDA is the most frequently measured biomarker of oxidative stress, namely lipid peroxidation. Oxidative stress is generally assumed to be associated with disease and to increase with age. Here, we review and discuss the literature concerning circulating and excretory MDA as a biomarker of lipid peroxidation in aging subjects with regard to health and disease, such as kidney disease, erectile dysfunction, and COVID-19. (2) Methods: Scientific articles, notably those reporting on circulating (plasma, serum) and urinary MDA, which concern health and disease, and which appeared in PubMed were considered; they formed the basis for evaluating the potential increase in oxidative stress, particularly lipid peroxidation, as humans age. (3) Results and Conclusions: The results reported in the literature thus far are contradictory. The articles considered in the present study are not supportive of the general view that oxidative stress increases with aging. Many functions of several organs, including the filtration efficiency of the kidneys, are physiologically reduced in men and women as they age. This effect is likely to result in the apparent "accumulation" of biomarkers of oxidative stress, concomitantly with the "accumulation" of biomarkers of an organ's function, such as creatinine. How free and conjugated MDA forms are transported in various organs (including the brain) and how they are excreted in the urine via the kidney is not known, and investigating these questions should be the objective of forthcoming studies. The age- and gender-related increase in circulating creatinine might be a useful factor to be taken into consideration when investigating oxidative stress and aging.

Cyclometalated ruthenium (II) complexes induced HeLa cell apoptosis through intracellular reductive injury

The main challenge of cancer chemotherapy is the resistance of tumor cells to oxidative damage. Herein, we proposed a novel antitumor strategy: cyclic metal‑ruthenium (Ru) complexes mediate reductive damage to kill tumor cells. We designed and synthesized Ru(II) complexes with β-carboline as ligands: [Ru (phen)2(NO2-Ph-βC)](PF6) (RuβC-7) and [Ru(phen)2(1-Ph-βC)](PF6) (RuβC-8). In vitro experimental results showed that RuβC-7 and RuβC-8 can inhibit cell proliferation, promote mitochondrial abnormalities, and induce DNA damage. Interestingly, RuβC-7 with SOD activity could reduce intracellular reactive oxygen species (ROS) levels, while RuβC-8 has the opposite effect. Accordingly, this study identified the reductive damage mechanism of tumor apoptosis, and may provide a new ideas for the design of novel metal complexes.

Shear Stress and ROS Dual-Responsive RBC-Hitchhiking Nanoparticles for Atherosclerosis Therapy

Atherosclerosis (AS), a leading cause of death worldwide, is a chronic inflammatory disease rich in lipids and reactive oxygen species (ROS) within plaques. Therefore, lowering lipid and ROS levels is effective in treating AS and reducing AS-induced mortality. In this study, an intelligent biomimetic drug delivery system that specifically responded to both shear stress and ROS microenvironment was developed, consisting of red blood cells (RBCs) and cross-linked polyethyleneimine nanoparticles (SA PEI) loaded with a lipid-lowering drug simvastatin acid (SA), and RBCs were self-assembled with SA PEI to obtain biresponsive SA PEI@RBCs for the treatment of AS. SA PEI could achieve sustained release of SA in response to ROS and reduce ROS and lipid levels to achieve the purpose of treating AS. Shear stress model experiments showed that SA PEI@RBCs could respond to the high shear stress level (100 dynes/cm2) at plaques, realizing the desorption and enrichment of SA PEI and improving the therapeutic efficiency of SA PEI@RBCs. In vitro and in vivo experiments have confirmed that SA PEI@RBCs exhibits better in vivo safety and therapeutic efficacy than SA PEI and free SA. Therefore, shaping SA PEI@RBCs into a biomimetic drug delivery system with dual sensitivity to ROS and shear stress is an effective strategy and treatment to facilitate their delivery into plaques.

The Redox-Active Manganese(III) Porphyrin, MnTnBuOE-2-PyP5+, Impairs the Migration and Invasion of Non-Small Cell Lung Cancer Cells, Either Alone or Combined with Cisplatin

Manganese(III) porphyrin MnTnBuOE-2-PyP5+ (MnBuOE, BMX-001) is a third-generation redox-active cationic substituted pyridylporphyrin-based drug with a good safety/toxicity profile that has been studied in several types of cancer. It is currently in four phase I/II clinical trials on patients suffering from glioma, head and neck cancer, anal squamous cell carcinoma and multiple brain metastases. There is yet an insufficient understanding of the impact of MnBuOE on lung cancer. Therefore, this study aims to fill this gap by demonstrating the effects of MnBuOE on non-small cell lung cancer (NSCLC) A549 and H1975 cell lines. The cytotoxicity of MnBuOE alone or combined with cisplatin was evaluated by crystal violet (CV) and/or 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-Tetrazolium (MTS) reduction assays. Intracellular ROS levels were assessed using two fluorescent probes. Furthermore, the impact of MnBuOE alone or in combination with cisplatin on collective cell migration, individual chemotactic migration and chemoinvasion was assessed using the wound-healing and transwell assays. The expression of genes related to migration and invasion was assessed through RT-qPCR. While MnBuOE alone decreased H1975 cell viability at high concentrations, when combined with cisplatin it markedly reduced the viability of the more invasive H1975 cell line but not of A549 cell line. However, MnBuOE alone significantly decreased the migration of both cell lines. The anti-migratory effect was more pronounced when MnBuOE was combined with cisplatin. Finally, MnBuOE alone or combined with cisplatin significantly reduced cell invasion. MnBuOE alone or combined with cisplatin downregulated MMP2, MMP9, VIM, EGFR and VEGFA and upregulated CDH1 in both cell lines. Overall, our data demonstrate the anti-metastatic potential of MnBuOE for the treatment of NSCLC.

Pathways to healing: Plants with therapeutic potential for neurodegenerative diseases

Some of the greatest challenges in medicine are the neurodegenerative diseases (NDs), which remain without a cure and mostly progress to death. A companion study employed a toolkit methodology to document 2001 plant species with ethnomedicinal uses for alleviating pathologies relevant to NDs, focusing on its relevance to Alzheimer's disease (AD). This study aimed to find plants with therapeutic bioactivities for a range of NDs. 1339 of the 2001 plant species were found to have a bioactivity from the literature of therapeutic relevance to NDs such as Parkinson's disease, Huntington's disease, AD, motor neurone diseases, multiple sclerosis, prion diseases, Neimann-Pick disease, glaucoma, Friedreich's ataxia and Batten disease. 43 types of bioactivities were found, such as reducing protein misfolding, neuroinflammation, oxidative stress and cell death, and promoting neurogenesis, mitochondrial biogenesis, autophagy, longevity, and anti-microbial activity. Ethno-led plant selection was more effective than random selection of plant species. Our findings indicate that ethnomedicinal plants provide a large resource of ND therapeutic potential. The extensive range of bioactivities validate the usefulness of the toolkit methodology in the mining of this data. We found that a number of the documented plants are able to modulate molecular mechanisms underlying various key ND pathologies, revealing a promising and even profound capacity to halt and reverse the processes of neurodegeneration.

Selected herbicides screened for toxicity and analysed as inhibitors of both cholinesterases

Sets of 346 herbicides in use and 163 outdated no longer in use were collected from open access online sources and compared in silico with cholinesterases inhibitors (ChI) and drugs in terms of physicochemical profile and estimated toxic effects on human health. The screening revealed at least one potential adverse consequence for each herbicide class assigned according to their mode of action on weeds. The classes with most toxic warnings were K1, K3/N, F1 and E. The selection of 11 commercial herbicides for in vitro biological tests on human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), the enzymes involved in neurotoxicity and detoxification of various xenobiotics, respectively, was based mainly on the structural similarity with inhibitors of cholinesterases. Organophosphate anilofos and oxyacetanilide flufenacet were the most potent inhibitors of AChE (25 μM) and BChE (6.4 μM), respectively. Glyphosate, oxadiazon, tembotrione and terbuthylazine were poor inhibitors with an estimated IC₅₀ above 100 μM, while for glyphosate the IC₅₀ was above 1 mM. Generally, all of the selected herbicides inhibited with a slight preference towards BChE. Cytotoxicity assays showed that anilofos, bensulide, butamifos, piperophos and oxadiazon were cytotoxic for hepatocytes (HepG2) and neuroblastoma cell line (SH-SY5Y). Time-independent cytotoxicity accompanied with induction of reactive oxygen species indicated rapid cell death in few hours. Our results based on in silico and in vitro analyses give insight into the potential toxic outcome of herbicides in use and can be applied in the design of new molecules with a less hazardous impact on humans and the environment.

Safety assessment and redox status in rats after chronic exposure to cannabidiol and cannabigerol

Cannabidiol (CBD) and cannabigerol (CBG) are the two main non-psychotropic phytocannabinoids with high application potential in drug development. Both substances are redox-active and are intensively investigated for their cytoprotective and antioxidant action in vitro. In this study, we focused on an in vivo safety evaluation and the effect of CBD and CBG on the redox status in rats in a 90-d experiment. The substances were administered orogastrically in a dose of 0.66 mg synthetic CBD or 0.66 mg/1.33 mg CBG/kg/day. CBD produced no changes in the red or white blood count or biochemical blood parameters in comparison to the control. No deviations in the morphology or histology of the gastrointestinal tract and liver were observed. After 90 d of CBD exposure, a significant improvement in redox status was found in the blood plasma and liver. The concentration of malondialdehyde and carbonylated proteins was reduced compared to the control. In contrast to CBD, total oxidative stress was significantly increased and this was accompanied by an elevated level of malondialdehyde and carbonylated proteins in CBG-treated animals. Hepatotoxic (regressive changes) manifestations, disruption in white cell count, and alterations in the ALT activity, level of creatinine and ionized calcium were also found in CBG-treated animals. Based on liquid chromatography-mass spectrometry analysis, CBD/CBG accumulated in rat tissues (in the liver, brain, muscle, heart, kidney and skin) at a low ng level per gram. Both CBD and CBG molecular structures include a resorcinol moiety. In CBG, there is an extra dimethyloctadienyl structural pattern, which is most likely responsible for the disruption to the redox status and hepatic environment. The results are valuable to further investigation of the effects of CBD on redox status and should contribute towards opening up critical discussion on the applicability of other non-psychotropic cannabinoids.

How the Disruption of Mitochondrial Redox Signalling Contributes to Ageing

In the past, mitochondrial reactive oxygen species (mtROS) were considered a byproduct of cellular metabolism. Due to the capacity of mtROS to cause oxidative damage, they were proposed as the main drivers of ageing and age-related diseases. Today, we know that mtROS are cellular messengers instrumental in maintaining cellular homeostasis. As cellular messengers, they are produced in specific places at specific times, and the intensity and duration of the ROS signal determine the downstream effects of mitochondrial redox signalling. We do not know yet all the processes for which mtROS are important, but we have learnt that they are essential in decisions that affect cellular differentiation, proliferation and survival. On top of causing damage due to their capacity to oxidize cellular components, mtROS contribute to the onset of degenerative diseases when redox signalling becomes dysregulated. Here, we review the best-characterized signalling pathways in which mtROS participate and those pathological processes in which they are involved. We focus on how mtROS signalling is altered during ageing and discuss whether the accumulation of damaged mitochondria without signalling capacity is a cause or a consequence of ageing.

Quercetin Reprograms Immunometabolism of Macrophages via the SIRT1/PGC-1α Signaling Pathway to Ameliorate Lipopolysaccharide-Induced Oxidative Damage

The redox system is closely related to changes in cellular metabolism. Regulating immune cell metabolism and preventing abnormal activation by adding antioxidants may become an effective treatment for oxidative stress and inflammation-related diseases. Quercetin is a naturally sourced flavonoid with anti-inflammatory and antioxidant activities. However, whether quercetin can inhibit LPS-induced oxidative stress in inflammatory macrophages by affecting immunometabolism has been rarely reported. Therefore, the present study combined cell biology and molecular biology methods to investigate the antioxidant effect and mechanism of quercetin in LPS-induced inflammatory macrophages at the RNA and protein levels. Firstly, quercetin was found to attenuate the effect of LPS on macrophage proliferation and reduce LPS-induced cell proliferation and pseudopodia formation by inhibiting cell differentiation, as measured by cell activity and proliferation. Subsequently, through the detection of intracellular reactive oxygen species (ROS) levels, mRNA expression of pro-inflammatory factors and antioxidant enzyme activity, it was found that quercetin can improve the antioxidant enzyme activity of inflammatory macrophages and inhibit their ROS production and overexpression of inflammatory factors. In addition, the results of mitochondrial morphology and mitochondrial function assays showed that quercetin could upregulate the mitochondrial membrane potential, ATP production and ATP synthase content decrease induced by LPS, and reverse the mitochondrial morphology damage to a certain extent. Finally, Western blotting analysis demonstrated that quercetin significantly upregulated the protein expressions of SIRT1 and PGC-1α, that were inhibited by LPS. And the inhibitory effects of quercetin on LPS-induced ROS production in macrophages and the protective effects on mitochondrial morphology and membrane potential were significantly decreased by the addition of SIRT1 inhibitors. These results suggested that quercetin reprograms the mitochondria metabolism of macrophages through the SIRT1/PGC-1α signaling pathway, thereby exerting its effect of alleviating LPS-induced oxidative stress damage.

Epigenetic Modifications Induced by the Gut Microbiota May Result from What We Eat: Should We Talk about Precision Diet in Health and Disease?

Diet is currently considered one of the most important adjustable determinants of human health. The gut microbiota, the collection of microorganisms that inhabit (mainly) the distal bowel, has recently been shown to ensure critical physiological functions, such as immune, metabolic and neuropsychiatric. Many of these biological effects result from the production of bacterial metabolites that may target host cells, tissues and organs. In line with this rationale, epigenetics has brought new insights to our understanding of how environmental factors influence gene expression and, interestingly, gut microbiota metabolites have recently been proposed as novel and significant inducers of epigenetic modifications. Efforts have been dedicated to unveil how the production of specific metabolites influences the activity of epigenetic writers and erasers in order to establish a mechanistic link between gut microbiota, epigenetic modifications and health. Recent data is now evidencing how specific microbial metabolites shape the epigenetic landscape of eukaryotic cells, paving new avenues for innovative therapeutic strategies relying on diet-driven microbiota: epigenetic interactions. Herein is discussed the impact of diet on gut microbiota and the molecular mechanisms underlying microbiota–host interactions, highlighting the influence of diet on microbiota metabolome and how this may induce epigenetic modifications in host cells. Furthermore, it is hypothesized that epigenetics may be a key process transducing the effects of diet on gut microbiota with consequences for health and disease. Accordingly, innovating strategies of disease prevention based on a “precision diet”, a personalized dietary planning according to specific epigenetic targets, are discussed.

Early Detection Is the Best Prevention-Characterization of Oxidative Stress in Diabetes Mellitus and Its Consequences on the Cardiovascular System

Previous studies demonstrated an important role of oxidative stress in the pathogenesis of cardiovascular disease (CVD) in diabetic patients due to hyperglycemia. CVD remains the leading cause of premature death in the western world. Therefore, diabetes mellitus-associated oxidative stress and subsequent inflammation should be recognized at the earliest possible stage to start with the appropriate treatment before the onset of the cardiovascular sequelae such as arterial hypertension or coronary artery disease (CAD). The pathophysiology comprises increased reactive oxygen and nitrogen species (RONS) production by enzymatic and non-enzymatic sources, e.g., mitochondria, an uncoupled nitric oxide synthase, xanthine oxidase, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX). Considering that RONS originate from different cellular mechanisms in separate cellular compartments, adequate, sensitive, and compartment-specific methods for their quantification are crucial for early detection. In this review, we provide an overview of these methods with important information for early, appropriate, and effective treatment of these patients and their cardiovascular sequelae.

Prognostic Role of Vascular Endothelial Growth Factor and Correlation with Oxidative Stress Markers in Locally Advanced and Metastatic Ovarian Cancer Patients

BACKGROUND

Vascular endothelial growth factor (VEGF) plays an important role in tumor progression in ovarian cancer, but the complex mechanism and interaction with oxidative stress are not fully understood.

METHODS

A prospective study included 52 patients with ovarian adenocarcinoma stage IIIA-IV. Serum VEGF and reactive oxygen species (ROS) such as malondialdehyde and ceruloplasmin were measured.

RESULTS

VEGF levels were elevated (mean 1014.7 ± 165 pg/mL), especially in patients with macroscopic residual disease (1058 vs. 810 pg/mL, p = 0.0001). Median progression-free survival (PFS) and overall survival (OS) were 6 and 40 months in patients with a very high VEGF (over 1200 pg/mL), 11 and 48 months in patients with VEGF between 1000-1200 pg/mL, 18 and 84 months in patients with VEGF between 800-1000 pg/mL, and not reached in patients with normal VEGF. Increased VEGF values were associated with a 2.6-fold increased risk of disease progression (HR = 2.60, 95% CI 1.69-3.99), and a 1.4-fold increased risk of death (HR = 1.4, 95% CI 1.15-1.91, p = 0.002). Receiver operator characteristic (ROC) curves were used to validate VEGF as a prognostic factor and the area under the curve (AUC) was 0.814, p = 0.036 for PFS and 0.729, p = 0.043, for OS. There was a positive correlation between VEGF and malondialdehyde, Pearson coefficient of 0.35, p = 0.0001.

CONCLUSIONS

VEGF and malondialdehyde are important prognostic markers in ovarian cancer, especially in macroscopic residual disease, and there is a positive correlation between angiogenesis and oxidative stress.

Selected biomarkers of oxidative stress in healthy Beagle dogs: A preliminary study

Introduction

While oxidative stress has been studied in pathologic conditions in dogs, data in presumably healthy dogs and standardized protocols are lacking. This work purposed to bridge the gap by presenting provisional physiological ranges for oxidative stress biomarkers in a group of Beagle dogs.

Methods

Based on our long-standing clinical expertise in the field of oxidative stress, nine plasma biomarkers of oxidative stress were evaluated for their concentrations (mean ± SD) in 14 healthy adult Beagle dogs.

Results

Selected biomarkers were: vitamins C (7.90 ± 1.36 μg/mL) and E (34.1 ± 6.63 μg/mL), zinc (0.80 ± 0.17 mg/L), copper (0.54 ± 0.048 mg/L), selenium (256 ± 25.7 μg/L), total and oxidized glutathione (822 ± 108 μM and 3.56 ± 1.76 μM), myeloperoxidase (67.4 ± 56.2 ng/mL), and isoprostanes (340 ± 95.3 ng/mL). Glutathione peroxidase activity and superoxide anion production in whole blood were also measured. Glutathione peroxidase activity was 473 ± 34.0 IU/g of hemoglobin and superoxide anion production in whole blood was 18,930 ± 12,742 counts per 30 min. Reduced glutathione/oxidized glutathione and copper/zinc ratios were, respectively, 280 ± 139 and 0.70 ± 0.15. Sex-related differences were recorded for zinc (p = 0.0081), copper/zinc ratio (p = 0.0036) and plasma isoprostanes (p = 0.0045).

Conclusion

Provisional physiological norms covering 95% of our group were proposed for each biomarker and should be of interest for future studies of canine oxidative stress.

Systemic inflammation factors as survival prognosis markers in ovarian neoplasm and the relationship with cancer-associated inflammatory mediators-a review

At the level of the genital system, ovarian neoplasm is the most frequent cause of morbidity and mortality. In the specialized literature, the coexistence of an inflammatory process is admitted from the early stages of the evolution of this pathology. Starting from the importance of this process, both in determinism and in the evolution of carcinogenesis and summarizing the field of knowledge, for this study we considered two objectives: the first was the presentation of the pathogenic mechanism, through which chronic +ovarian inflammation is involved in the process of carcinogenesis, and the second is the justification of the clinical utility of the three parameters, accepted as biomarkers of systemic inflammation: neutrophil-lymphocyte ratio, platelet lymphocyte ratio, and lymphocyte-monocyte ratio in the assessment of prognosis. The study highlights the acceptance of these hematological parameters, with practical utility, as prognostic biomarkers in ovarian cancer, based on the intrinsic link with cancer-associated inflammatory mediators. Based on the data from the specialized literature, the conclusion is that in ovarian cancer, the inflammatory process induced by the presence of the tumor, induces changes in the types of circulating leukocytes, with immediate effects on the markers of systemic inflammation.

MicroRNAs in the Regulation of NADPH Oxidases in Vascular Diabetic and Ischemic Pathologies: A Case for Alternate Inhibitory Strategies?

Since their discovery in the vasculature, different NADPH oxidase (NOX) isoforms have been associated with numerous complex vascular processes such as endothelial dysfunction, vascular inflammation, arterial remodeling, and dyslipidemia. In turn, these often underlie cardiovascular and metabolic pathologies including diabetes mellitus type II, cardiomyopathy, systemic and pulmonary hypertension and atherosclerosis. Increasing attention has been directed toward miRNA involvement in type II diabetes mellitus and its cardiovascular and metabolic co-morbidities in the search for predictive and stratifying biomarkers and therapeutic targets. Owing to the challenges of generating isoform-selective NOX inhibitors (NOXi), the development of specific NOXis suitable for therapeutic purposes has been hindered. In that vein, differential regulation of specific NOX isoforms by a particular miRNA or combina-tion thereof could at some point become a reasonable approach for therapeutic targeting under some circumstances. Whereas administration of miRNAs chronically, or even acutely, to patients poses its own set of difficulties, miRNA-mediated regulation of NOXs in the vasculature is worth surveying. In this review, a distinct focus on the role of miRNAs in the regulation of NOXs was made in the context of type II diabetes mellitus and ischemic injury models.

The protective effect of proanthocyanidins on the psoriasis-like cell models via PI3K/AKT and HO-1

Background

Inflammation and oxidative stress (OS) are important contributors to psoriasis pathogenesis. Proanthocyanidins (PCs) have anti-inflammatory and anti-oxidative activities. Previously, we discovered that PCs alleviated psoriasis-like mice symptoms, likely via mitigating inflammation and OS damage.

Objective

To elucidate the protective mechanism underlying PCs against the damage of TNF-ɑ-induced psoriasis-like cell models.

Methods

Psoriasis-like cell models were established with 7.5 ng/mL TNF-ɑ and then subjected to different-concentrations PCs treatment. Finally, inflammatory and oxidative parameters were determined. Besides, LY294002 (PI3K inhibitor) and ZnPP (HO-1 inhibitor) were employed to investigate the roles of PI3K/AKT and HO-1 in PCs against psoriasis-like cell models.

Results

After TNF-α treatment, cells organized tightly and proliferated greatly (P<0.01); HO-1 expression dropped obviously, along with the increased OS/inflammatory indicators and the decreased antioxidants (P<0.05); consequently, psoriasis-like cell models were well established. In the presence of PCs, nevertheless, the proliferation rate and number of psoriasis-like cells evidently decreased (P<0.01), accompanied with enhanced HO-1 and antioxidants, and lowered OS/inflammatory indicators as well as phosphorylated JAK2/STAT3/PI3/AKT (P<0.01). Similar changes appeared after LY294002 pretreatment, regardless of PCs or not. But after ZnPP pretreatment with or without PCs, the opposite occurred.

Conclusion

The study reveals that PCs can suppress psoriasis-like cell proliferation and reduce inflammatory/OS damage through PI3K/AKT inhibition and HO-1 activation, thus promising a candidate for PCs in treating psoriasis.

MnTnHex-2-PyP5+ Displays Anticancer Properties and Enhances Cisplatin Effects in Non-Small Cell Lung Cancer Cells

The manganese(III) porphyrin MnTnHex-2-PyP5+ (MnTnHex) is a potent superoxide dismutase mimic and modulator of redox-based transcriptional activity that has been studied in the context of different human disease models, including cancer. Nevertheless, for lung cancer, hardly any information is available. Thus, the present work aims to fill this gap and reports the effects of MnTnHex in non-small cell lung cancer (NSCLC) cells, more specifically, A549 and H1975 cells, in vitro. Both cell lines were initially characterized in terms of innate levels of catalase, glutathione peroxidase 1, and peroxiredoxins 1 and 2. To assess the effect of MnTnHex in NSCLC, alone or in combination with cisplatin, endpoints related to the cell viability, cell cycle distribution, cell motility, and characterization of the volatile carbonyl compounds (VCCs) generated in the extracellular medium (i.e., exometabolome) were addressed. The results show that MnTnHex as a single drug markedly reduced the viability of both NSCLC cell lines, with some IC50 values reaching sub-micromolar levels. This redox-active drug also altered the cell cycle distribution, induced cell death, and increased the cytotoxicity pattern of cisplatin. MnTnHex also reduced collective cell migration. Finally, the metabolomics study revealed an increase in the levels of a few VCCs associated with oxidative stress in MnTnHex-treated cells. Altogether these results suggest the therapeutic potential of MnTnHex to be further explored, either alone or in combination therapy with cisplatin, in NSCLC.

A double-edged sword: ROS related therapies in the treatment of psoriasis

In the onset and progression of psoriasis, redox imbalance is a vital factor. It's widely accepted that too much reactive oxygen species (ROS) always make psoriasis worse. Recent research, however, has shown that the accumulation of ROS is not entirely detrimental, as it helps reduce psoriasis lesions by inhibiting epidermal proliferation and keratinocyte death. As a result, ROS appears to have two opposing effects on the treatment of psoriasis. In this review, the current ROS-related therapies for psoriasis, including basic and clinical research, are presented. Additionally, the design and therapeutic benefits of various drug delivery systems and therapeutic approaches are examined, and a potential balance between anti-oxidative stress and ROS accumulation is also trying to be investigated.

A versatile multiplexed assay to quantify intracellular ROS and cell viability in 3D on-a-chip models

Reactive oxygen species (ROS) have different properties and biological functions. They contribute to cell signaling and, in excessive amounts, to oxidative stress (OS). Although ROS is pivotal in a wide number of physiological systems and pathophysiological processes, direct quantification in vivo is quite challenging and mainly limited to in vitro studies. Even though advanced in vitro cell culture techniques, like on-a-chip culture, have overcome the lack of crucial in vivo-like physiological aspects in 2D culture, the majority of in vitro ROS quantification studies are generally performed in 2D. Here we report the development, application, and validation of a multiplexed assay to quantify ROS and cell viability in organ-on-a-chip models. The assay utilizes three dyes to stain live cells for ROS, dead cells, and DNA. Confocal images were analyzed to quantify ROS probes and determine the number of nuclei and dead cells. We found that, in contrast to what has been reported with 2D cell culture, on-a-chip models are more prone to scavenge ROS rather than accumulate them. The assay is sensitive enough to distinguish between different phenotypes of endothelial cells (ECs) based on the level of OS to detect higher level in tumor than normal cells. Our results indicate that the use of physiologically relevant models and this assay could help unravelling the mechanisms behind OS and ROS accumulation. A further step could be taken in data analysis by implementing AI in the pipeline to also analyze images for morphological changes to have an even broader view of OS mechanism.

Janus, or the Inevitable Battle Between Too Much and Too Little Oxygen

Significance: Oxygen levels are key regulators of virtually every living mammalian cell, under both physiological and pathological conditions. Starting from embryonic and fetal development, through the growth, onset, and progression of diseases, oxygen is a subtle, although pivotal, mediator of key processes such as differentiation, proliferation, autophagy, necrosis, and apoptosis. Hypoxia-driven modifications of cellular physiology are investigated in depth or for their clinical and translational relevance, especially in the ischemic scenario. Recent Advances: The mild or severe lack of oxygen is, undoubtedly, related to cell death, although abundant evidence points at oscillating oxygen levels, instead of permanent low pO₂, as the most detrimental factor. Different cell types can consume oxygen at different rates and, most interestingly, some cells can shift from low to high consumption according to the metabolic demand. Hence, we can assume that, in the intracellular compartment, oxygen tension varies from low to high levels depending on both supply and consumption. Critical Issues: The positive balance between supply and consumption leads to a pro-oxidative environment, with some cell types facing hypoxia/hyperoxia cycles, whereas some others are under fairly constant oxygen tension. Future Directions: Within this frame, the alterations of oxygen levels (dysoxia) are critical in two paradigmatic organs, the heart and brain, under physiological and pathological conditions and the interactions of oxygen with other physiologically relevant gases, such as nitric oxide, can alternatively contribute to the worsening or protection of ischemic organs. Further, the effects of dysoxia are of pivotal importance for iron metabolism. Antioxid. Redox Signal. 37, 972-989.

Endothelial and Vascular Smooth Muscle Dysfunction in Hypertension

The development of essential hypertension involves several factors. Vascular dysfunction, characterized by endothelial dysfunction, low-grade inflammation and structural remodeling, plays an important role in the initiation and maintenance of essential hypertension. Although the mechanistic pathways by which essential hypertension develops are poorly understood, several pharmacological classes available on the clinical settings improve blood pressure by interfering in the cardiac output and/or vascular function. This review is divided in two major sections. The first section depicts the major molecular pathways as renin angiotensin aldosterone system (RAAS), endothelin, nitric oxide signalling pathway and oxidative stress in the development of vascular dysfunction. The second section describes the role of some pharmacological classes such as i) RAAS inhibitors, ii) dual angiotensin receptor-neprilysin inhibitors, iii) endothelin-1 receptor antagonists, iv) soluble guanylate cyclase modulators, v) phosphodiesterase type 5 inhibitors and vi) sodium-glucose cotransporter 2 inhibitors in the context of hypertension. Some classes are already approved in the treatment of hypertension, but others are not yet approved. However, due to their potential benefits these classes were included.

Development and in vivo validation of small interfering RNAs targeting NOX3 to prevent sensorineural hearing loss

The reactive oxygen species (ROS)-generating enzyme NOX3 has recently been implicated in the pathophysiology of several acquired forms of sensorineural hearing loss, including cisplatin-, noise- and age-related hearing loss. NOX3 is highly and specifically expressed in the inner ear and therefore represents an attractive target for specific intervention aiming at otoprotection. Despite the strong rationale to inhibit NOX3, there is currently no specific pharmacological inhibitor available. Molecular therapy may represent a powerful alternative. In this study, we developed and tested a collection of small interfering (si) RNA constructs to establish a proof of concept of NOX3 inhibition through local delivery in the mouse inner ear. The inhibitory potential of 10 different siRNA constructs was first assessed in three different cells lines expressing the NOX3 complex. Efficacy of the most promising siRNA construct to knock-down NOX3 was then further assessed in vivo, comparing middle ear delivery and direct intracochlear delivery through the posterior semi-circular canal. While hearing was completely preserved through the intervention, a significant downregulation of NOX3 expression in the mouse inner ear and particularly in the spiral ganglion area at clinically relevant levels (>60%) was observed 48 h after treatment. In contrast to successful intracochlear delivery, middle ear administration of siRNA failed to significantly inhibit Nox3 mRNA expression. In conclusion, intracochlear delivery of NOX3-siRNAs induces a robust temporal NOX3 downregulation, which could be of relevance to prevent predictable acute insults such as cisplatin chemotherapy-mediated ototoxicity and other forms of acquired hearing loss, including post-prevention of noise-induced hearing loss immediately after trauma. Successful translation of our concept into an eventual clinical use in humans will depend on the development of atraumatic and efficient delivery routes into the cochlea without a risk to induce hearing loss through the intervention.

Cytoprotective Activity of Newly Synthesized 3-(Arylmethylamino)-6-Methyl-4-Phenylpyridin-2(1H)-Ones Derivatives

Currently, studies are being conducted on the possible role of the cytoprotective effect of biologically active substances in conditions of cerebral hypoxia or cardiomyopathies. At the same time, oxidative stress is considered one of the important mechanisms of cellular cytotoxicity and a target for the action of cytoprotectors. The aim of this study is to search for derivatives of 3-(arylmethylamino)-6-methyl-4-phenylpyridin-2(1H)-ones. The probability of cytoprotective action was assessed by measuring cell viability using two tests (with neutral red dye and MTT test). It was found that some derivatives of 3-(arylmethylamino)-6-methyl-4-phenylpyridin-2(1H)-ones under the conditions of our experiment had a pronounced cytoprotective activity, providing better cell survival in vitro, including the MTT test and conditions of blood hyperviscosity. To correlate the obtained results in vitro, molecular docking of the synthesized derivatives was also carried out. The standard drug omeprazole (co-crystallized with the enzyme) was used as a standard. It was shown that all synthesized derivatives of 3-(arylmethylamino)-6-methyl-4-phenylpyridin-2(1H)-ones had higher affinity for the selected protein than the standard gastro-cytoprotector omeprazole. The studied derivatives of 3-(arylmethylamino)-6-methyl-4-phenylpyridin-2(1H)-ones also fully satisfy Lipinski’s rule of five (RO5), which increases their chances for possible use as orally active drugs with good absorption ability and moderate lipophilicity. Thus, the results obtained make it possible to evaluate derivatives of 3-(arylmethylamino)-6-methyl-4-phenylpyridin-2(1H)-ones as having a relatively high cytoprotective potential.

The Examination of the Influence of Caffeinated Coffee Consumption on the Concentrations of Serum Prolactin and Selected Parameters of the Oxidative-Antioxidant Balance in Young Adults: A Preliminary Report

We verified whether caffeinated coffee consumption influenced the concentrations of prolactin (PRL) and oxidative stress parameters: total antioxidant status (TAS), ferric reducing antioxidant power (FRAP), total oxidant status (TOS), oxidative stress index (OSI), advanced oxidation protein products (AOPP), uric acid (UA), total bilirubin (T-Bil), albumin (ALB), iron (Fe), calcium (Ca), magnesium (Mg), and inflammatory marker C-reactive protein (CRP)-in blood sera obtained at 15, 60, and 120 minutes after caffeinated coffee intake, in relation to the fasting point. The study participants were 33 young, healthy, nonsmoking volunteers (15 men, 18 women) aged 19-29 years. PRL concentrations significantly decreased (p < 0.05) after consumption, except at time point 15' in men (p > 0.05). In women, FRAP levels significantly increased over time, and significant changes were also observed for UA at 120' and ALB at 15'. In men, significant changes were found for levels of AOPP at 15', T-Bil and ALB at 15', iron at 60' and 120', and calcium at 120'. There were no significant differences in the levels of other examined parameters between the defined time points. In conclusion, the substances contained in caffeinated coffee decrease the level of prolactin and may also have an impact on selected parameters of oxidative stress, which could be the basis of future research focused on the identification of new therapeutic targets.

Comparison of Five Oxidative Stress Biomarkers in Vegans and Omnivores from Germany and Finland

When the amount of reactive oxygen species produced by human metabolism cannot be balanced by antioxidants, this phenomenon is commonly referred to as oxidative stress. It is hypothesised that diets with high amounts of plant food products may have a beneficial impact on oxidative stress status. However, few studies have examined whether a vegan diet is associated with lower oxidative stress compared to an omnivorous diet. The present cross-sectional study aimed to compare the levels of five oxidative stress biomarkers in vegans and omnivores. Data of 36 vegans and 36 omnivores from Germany and of 21 vegans and 18 omnivores from Finland were analysed. HPLC coupled with mass spectrometry or fluorescence detection and ELISA methods were used to measure the oxidative stress biomarkers malondialdehyde (MDA), protein carbonyls and 3-nitrotyrosine in plasma and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin F2α (8-iso-PGF2α) in 24 h urine. Analyses of variance and covariance, considering potential confounders, were used. Vegans and omnivores showed no differences in MDA and protein carbonyl concentrations. In Finnish but not in German vegans, the concentrations of 3-nitrotyrosine were lower compared to those in omnivores (p = 0.047). In Germany, vegans showed lower excretion levels of 8-iso-PGF2α than omnivores (p = 0.002) and with a trend also of 8-OHdG (p = 0.05). The sensitivity analysis suggests lower 8-iso-PGF2α excretion levels in women compared to men, independently of the dietary group. The present study contributes to expanding our knowledge of the relationship between diet and oxidative stress and showed that 3-nitrotyrosine, 8-OHdG and 8-iso-PGF2α tended to be lower in vegans. Furthermore, studies are recommended to validate the present findings.

Defining roles of specific reactive oxygen species (ROS) in cell biology and physiology

'Reactive oxygen species' (ROS) is a generic term that defines a wide variety of oxidant molecules with vastly different properties and biological functions that range from signalling to causing cell damage. Consequently, the description of oxidants needs to be chemically precise to translate research on their biological effects into therapeutic benefit in redox medicine. This Expert Recommendation article pinpoints key issues associated with identifying the physiological roles of oxidants, focusing on H₂O₂ and O₂^.-. The generic term ROS should not be used to describe specific molecular agents. We also advocate for greater precision in measurement of H₂O₂, O₂^.- and other oxidants, along with more specific identification of their signalling targets. Future work should also consider inter-organellar communication and the interactions of redox-sensitive signalling targets within organs and whole organisms, including the contribution of environmental exposures. To achieve these goals, development of tools that enable site-specific and real-time detection and quantification of individual oxidants in cells and model organisms are needed. We also stress that physiological O₂ levels should be maintained in cell culture to better mimic in vivo redox reactions associated with specific cell types. Use of precise definitions and analytical tools will help harmonize research among the many scientific disciplines working on the common goal of understanding redox biology.

Oxidative Stress in Ageing and Chronic Degenerative Pathologies: Molecular Mechanisms Involved in Counteracting Oxidative Stress and Chronic Inflammation

Ageing and chronic degenerative pathologies demonstrate the shared characteristics of high bioavailability of reactive oxygen species (ROS) and oxidative stress, chronic/persistent inflammation, glycation, and mitochondrial abnormalities. Excessive ROS production results in nucleic acid and protein destruction, thereby altering the cellular structure and functional outcome. To stabilise increased ROS production and modulate oxidative stress, the human body produces antioxidants, “free radical scavengers”, that inhibit or delay cell damage. Reinforcing the antioxidant defence system and/or counteracting the deleterious repercussions of immoderate reactive oxygen and nitrogen species (RONS) is critical and may curb the progression of ageing and chronic degenerative syndromes. Various therapeutic methods for ROS and oxidative stress reduction have been developed. However, scientific investigations are required to assess their efficacy. In this review, we summarise the interconnected mechanism of oxidative stress and chronic inflammation that contributes to ageing and chronic degenerative pathologies, including neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), cardiovascular diseases CVD, diabetes mellitus (DM), and chronic kidney disease (CKD). We also highlight potential counteractive measures to combat ageing and chronic degenerative diseases.

Inhaled nitric oxide: role in the pathophysiology of cardio-cerebrovascular and respiratory diseases

Nitric oxide (NO) is a key molecule in the biology of human life. NO is involved in the physiology of organ viability and in the pathophysiology of organ dysfunction, respectively. In this narrative review, we aimed at elucidating the mechanisms behind the role of NO in the respiratory and cardio-cerebrovascular systems, in the presence of a healthy or dysfunctional endothelium. NO is a key player in maintaining multiorgan viability with adequate organ blood perfusion. We report on its physiological endogenous production and effects in the circulation and within the lungs, as well as the pathophysiological implication of its disturbances related to NO depletion and excess. The review covers from preclinical information about endogenous NO produced by nitric oxide synthase (NOS) to the potential therapeutic role of exogenous NO (inhaled nitric oxide, iNO). Moreover, the importance of NO in several clinical conditions in critically ill patients such as hypoxemia, pulmonary hypertension, hemolysis, cerebrovascular events and ischemia-reperfusion syndrome is evaluated in preclinical and clinical settings. Accordingly, the mechanism behind the beneficial iNO treatment in hypoxemia and pulmonary hypertension is investigated. Furthermore, investigating the pathophysiology of brain injury, cardiopulmonary bypass, and red blood cell and artificial hemoglobin transfusion provides a focus on the potential role of NO as a protective molecule in multiorgan dysfunction. Finally, the preclinical toxicology of iNO and the antimicrobial role of NO-including its recent investigation on its role against the Sars-CoV2 infection during the COVID-19 pandemic-are described.

Caspase-4 and -5 Biology in the Pathogenesis of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disease of the gastrointestinal tract, associated with high levels of inflammatory cytokine production. Human caspases-4 and -5, and their murine ortholog caspase-11, are essential components of the innate immune pathway, capable of sensing and responding to intracellular lipopolysaccharide (LPS), a component of Gram-negative bacteria. Following their activation by LPS, these caspases initiate potent inflammation by causing pyroptosis, a lytic form of cell death. While this pathway is essential for host defence against bacterial infection, it is also negatively associated with inflammatory pathologies. Caspases-4/-5/-11 display increased intestinal expression during IBD and have been implicated in chronic IBD inflammation. This review discusses the current literature in this area, identifying links between inflammatory caspase activity and IBD in both human and murine models. Differences in the expression and functions of caspases-4, -5 and -11 are discussed, in addition to mechanisms of their activation, function and regulation, and how these mechanisms may contribute to the pathogenesis of IBD.

Obesity and Pancreatic Cancer: Recent Progress in Epidemiology, Mechanisms and Bariatric Surgery

More than 30% of people in the United States (US) are classified as obese, and over 50% are considered significantly overweight. Importantly, obesity is a risk factor not only for the development of metabolic syndrome but also for many cancers, including pancreatic ductal adenocarcinoma (PDAC). PDAC is the third leading cause of cancer-related death, and 5-year survival of PDAC remains around 9% in the U.S. Obesity is a known risk factor for PDAC. Metabolic control and bariatric surgery, which is an effective treatment for severe obesity and allows massive weight loss, have been shown to reduce the risk of PDAC. It is therefore clear that elucidating the connection between obesity and PDAC is important for the identification of a novel marker and/or intervention point for obesity-related PDAC risk. In this review, we discussed recent progress in obesity-related PDAC in epidemiology, mechanisms, and potential cancer prevention effects of interventions, including bariatric surgery with preclinical and clinical studies.

Redox Balance in β-Thalassemia and Sickle Cell Disease: A Love and Hate Relationship

β-thalassemia and sickle cell disease (SCD) are inherited hemoglobinopathies that result in both quantitative and qualitative variations in the β-globin chain. These in turn lead to instability in the generated hemoglobin (Hb) or to a globin chain imbalance that affects the oxidative environment both intracellularly and extracellularly. While oxidative stress is not among the primary etiologies of β-thalassemia and SCD, it plays a significant role in the pathogenesis of these diseases. Different mechanisms exist behind the development of oxidative stress; the result of which is cytotoxicity, causing the oxidation of cellular components that can eventually lead to cell death and organ damage. In this review, we summarize the mechanisms of oxidative stress development in β-thalassemia and SCD and describe the current and potential antioxidant therapeutic strategies. Finally, we discuss the role of targeted therapy in achieving an optimal redox balance.

"An apple a day keeps the doctor away": The potentials of apple bioactive constituents for chronic disease prevention

Apples are rich sources of selected micronutrients (e.g., iron, zinc, vitamins C and E) and polyphenols (e.g., procyanidins, phloridzin, 5′‐caffeoylquinic acid) that can help in mitigating micronutrient deficiencies (MNDs) and chronic diseases. This review provides an up‐to‐date overview of the significant bioactive compounds in apples together with their reported pharmacological actions against chronic diseases such as diabetes, cancer, and cardiovascular diseases. For consumers to fully gain these health benefits, it is important to ensure an all‐year‐round supply of highly nutritious and good‐quality apples. Therefore, after harvest, the physicochemical and nutritional quality attributes of apples are maintained by applying various postharvest treatments and hurdle techniques. The impact of these postharvest practices on the safety of apples during storage is also highlighted. This review emphasizes that advancements in postharvest management strategies that extend the storage life of apples should be optimized to better preserve the bioactive components crucial to daily dietary needs and this can help improve the overall health of consumers.

Rhinoceros serum labile plasma iron and associated redox potential: interspecific variation, sex bias and iron overload disorder disconnect

A consequence of the poaching crisis is that managed rhinoceros populations are increasingly important for species conservation. However, black rhinoceroses (BR; Diceros bicornis) and Sumatran rhinoceroses (SR; Dicerorhinus Sumatrensis) in human care often store excessive iron in organ tissues, a condition termed iron overload disorder (IOD). IOD research is impeded by the challenge of accurately monitoring body iron load in living rhinoceroses. The goals of this study were to (i) determine if labile plasma iron (LPI) is an accurate IOD biomarker and (ii) identify factors associated with iron-independent serum oxidative reduction potential (ORP). Serum (106 samples) from SRs (n = 8), BRs (n = 28), white rhinoceros (n = 24) and greater one-horned rhinoceros (GOH; n = 16) was analysed for LPI. Samples from all four species tested positive for LPI, and a higher proportion of GOH rhinoceros samples were LPI positive compared with those of the other three species (P < 0.05). In SRs, the only LPI-positive samples were those from individuals clinically ill with IOD, but samples from outwardly healthy individuals of the other three species were LPI positive. Serum ORP was lower in SRs compared with that in the other three species (P < 0.001), and iron chelation only reduced ORP in the GOH species (P < 0.01; ~5%). Serum ORP sex bias was revealed in three species with males exhibiting higher ORP than females (P < 0.001), the exception being the SR in which ORP was low for both sexes. ORP was not associated with age or serum iron concentrations (P ≥ 0.05), but was positively correlated with ferritin (P < 0.01). The disconnect between LPI and IOD was unanticipated, and LPI cannot be recommended as a biomarker of advanced rhino IOD. However, data provide valuable insight into the complex puzzle of rhinoceros IOD.

Serum albumin as a primary non-covalent binding protein for nitro-oleic acid

This work explores the interaction of 9/10-nitro-oleic acid (NO₂-OA) with human serum albumin (HSA). The molecular mechanism of the biological action of NO₂-OA is to our knowledge based on a reversible covalent reaction-Michael addition of nucleophilic amino acid residues of proteins. Since HSA is an important fatty acid transporter, a key question is whether NO₂-OA can bind covalently or non-covalently to HSA, similarly to oleic acid (OA), which can interact with the FA1-FA7 binding sites of the HSA molecule. ¹H NMR studies and competition analysis with OA and the drugs ibuprofen and warfarin were used to investigate a potential non-covalent binding mode. NO₂-OA/HSA binding was confirmed to compete with warfarin for FA-7 with significantly higher affinity. NO₂-OA competes with ibuprofen for FA-3 and FA-6, however, in contrast to the situation with warfarin, the binding affinities are not significantly different. The described interactions are based exclusively on non-covalent binding. No covalent binding of NO₂-OA to HSA was detected by MS/MS. More detailed studies based on MALDI-TOF-MS and Ellman's assay indicated that HSA can be covalently modified in the presence of NO₂-OA to a very limited extent. It was also shown that NO₂-OA has a higher affinity to HSA than that of OA.